test-ipv6.com / omgipv6day.com down

Matthew Luckie mjl at caida.org
Mon Jun 4 19:55:11 CDT 2012


> What's really needed is a service that looks up a given web page
> over IPv6 from behind a 1280 byte MTU link and reports if all the
> elements load or not.   It dumps a list of elements with success/fail.
>
> This would be useful to send the idiots that block ICMPv6 PTB yet
> send packets bigger than 1280 bytes out too.

http://www.wand.net.nz/scamper/

Works on MacOS X and FreeBSD.  It uses IPFW and rules 1-500 as
necessary.  Example below, showing a website sending > 1280 but
ignoring PTBs sent to it.

$ sudo scamper -F ipfw -I "tbit -t pmtud -u 'http://www.sapo.pt/'
2001:8a0:2104:ff:213:13:146:140"
tbit from 2001:470:d:4de:21f:3cff:fe20:bf4e to 2001:8a0:2104:ff:213:13:146:140
 server-mss 1460, result: pmtud-fail
 app: http, url: http://www.sapo.pt/
 [  0.048] TX SYN             64  seq = 0:0             
 [  0.254] RX SYN/ACK         64  seq = 0:1             
 [  0.255] TX                 60  seq = 1:1             
 [  0.255] TX                230  seq = 1:1(170)        
 [  0.450] RX                 60  seq = 1:171           
 [  0.469] RX               1460  seq = 1:171(1400)     
 [  0.469] TX PTB           1280  mtu = 1280
 [  0.470] RX               1460  seq = 1401:171(1400)  
 [  3.467] RX               1460  seq = 1:171(1400)     
 [  3.467] TX PTB           1280  mtu = 1280
 [  9.468] RX               1460  seq = 1:171(1400)     
 [  9.468] TX PTB           1280  mtu = 1280
 [ 21.471] RX               1460  seq = 1:171(1400)     
 [ 21.471] TX PTB           1280  mtu = 1280
 [ 31.933] RX RST             60  seq = 1:4294923802   



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